Supplemental valve to the equilibrium-pipe of the cornish engine



' u UNITED STATES PATENT OFFICE.

HENRY P. M. BLRKINBINE, OF PHILADELPHIA, PENNSYLVANIA.

SUPPLEMENTAL VALVE T0 THE EQUILIBRIUM-PIPE OF THE CORNISH ENGINE.

Specication forming part of Letters Patent No. 10,224, dated November15, 1853.

To all whom it may concern: y

Be it known that I, HENRY P. M. BRKIN- BINE, of Philadelphia, in thecounty of Philadelphia and State of Pennsylvania, have invented a newand Improved Mode of Regulating the Motion of Pumping-Engines; and I dohereby declare that the following is a full, clear, and exactdescription of the same, reference being had to the accompanyingdrawing, and to the letters of reference marked thereon.

My invention relates to that description of pumping machinery generallyknown among engineers as the Cornish engine 5 and it consists ofintercepting the passage through the equilibrium-pipe by means of anyconvenient valve apparatus in connection with machinery for regulatingthe same.

In order to enable others to make and use my invention, I will proceed,first, to describe, in general terms, the operation of an ordinaryCornish engine, and, second, my invention as applied to the same.

In the Cornish engine the stean from the boilers is admitted to thecylinder, which, pressing against the piston, raises the plunger of thepump to the required height, thus completing the upward stroke. Thecommunication with the boilers being now closed, the steam, which haslled the space in the cylinder on one side of the piston, is by theopening of the equilibrium-valve allowed to rush through a passage tothe other side, so that the pressure on each side of the piston will nowbe equal. The plunger will consequently descend by its own or anyadditional superincumbent weight and the Water be forced to the heightrequired. The opening and closing of the separate valves are caused bytappets on a plug-rod in conjunction with weighted levers and thecataract apparatus, the form and action of which are too familiar toengineers to need description.

The equi1ibriumpassage above referred to is in ordinary Cornish enginesuninterrupted-that is, when the equilibrium-valve is open the steam willrush with rapidity from one side of the piston to the other, causing anequally rapid descent of the plunger and its adj uncts. Now should therebe but a moderate head of water to force against this great rapidity isliable to cause shocks dangerous to the working parts of the engine.This would be especially felt in engines which raise water into astand-pipe, the level in the latter being liable to a great and sudden'fluctuation.

To obviate the difficulties arising from the above causes the removalfrom and addition of Weight to the plunger is the plan most generallyused, but one from which great ina convenience and delay arise.

I will now proceed to describe my invention and the manner in which itis applied to Cornish engines as a means of overcoming the objectionableshocks above mentioned.

The iigure in the drawing represents a sec tional view of that portionof the valve-noz'- zles which contains the equi.librium-valve with myimproved regulating apparatus attached.

A is the equilibrium-valve of the common double-beat principle; B, thevalve-seat, secured to the bottom of the chamber, with a flangeprojecting downward. This flange forms the seat for a supplementaryvalve C, which is of the common disk form. This valve, which is in thechamber below the equilibrium-valve, has a spindle D, which passesthrough a stuffing-box E at the bottom of the chamber. The end of thespindle screws into the hub of the miter-wheel F, which is allowed towork loosely in the center of the cross-bar G. Into the wheel F gearsanother wheel H on the shaft I, which is caused to revolve in eitherdirection by the handle .I on the vertical shaft K, in conjuncf tionwith a second pair of miter-wheels L and M.

It will be easily seen that on turning the handle J, which isconveniently situated for the attendant engineer, the supplementaryvalve C maybe brough t farther from or closer to the opening beneath theequilibrium-valve, and consequently the passage of the steam therefrommore orless obstructed at pleasure. Should the head of water to forceagainst be low, the engineer raises the valve toward the opening, thesteam in its attempts to escape to the opposite end of the piston willbe para tially arrested, and the plunger will descend with a gradual andeasy motion. Should the head of water, on the contrary, be high, theengineer turning the handle J in a coni trary direction, thesupplementary valve will be withdrawn from the opening and the steamallowed to have full play, the efcient head of Water being in itselfsufficient to arrest any sudden and dangerous descent ot' the plunger.

The supplementary valve has the additional advantage of giving theengineer power to arrest the engine fully at any portion of the downwardstroke of the plunger in case of accident.

Having now described the nature of my invention and the manner in whichthe same may be carried into effect,I Wish it to be understood that I donot contine myself to the particular form of supplementary valve hereindescribed or to the particular method in the equilibrium-passage, so asto regulate the rapidityof descent of the plunger according as the headof Water may require.

HENRY P. M. BIRKINBINE. Witnesses:

HENRY HoWsoN, JACOB H. YocUM, Jr.

